I'm going to use parallel leafs on the back of the jalopy I'm working on. The springs I have, have a short segment and a long segment. Working on Chrysler cars for years, the long segment always went towards the rear of the car. In this case, on this car, it would work out much easier if I turn the springs around. I still want to keep the shackle on the rear of the the spring. Anyone done this with good results?? Thanks, Gene.
I think doing that would have the opposite effect of what the Chrysler engineers designed. Shorter front segment equates to a stiffer spring pack and less flexing under load. Flip it around, and I suspect you'd have the opposite in my seat-of-the-pants engineering experience. If you go to one of the major leaf spring manufacturer's websites (like so: https://www.generalspringkc.com/ ) you can sort through the spring and their specs to find something close to what you need.
Agree. IMO, that would result is excessive spring wrap, even under mild acceleration. Really bad if the tires hook good and you have lots of HP.
No real HP here, using a 4 banger Chevy II motor. And I was thinking I could control spring wrap up with some cheappy slapper bars if needed. Gene.
OR......put a couple of extra spring clamps on the 'new' front section of leaf spring. This tends to stiffen the front leaves without destroying the ride comfort. 6sally6
Update, I just got off the phone with Detroit Spring. The guy said no problem, just be careful of spring wrap-up if the springs aren't stacked properly. So I guess I'm going to try it. Thanks again everyone. Gene.
If it's just a case of relocating the axle, and you already have spring packs, then just drill a new centering hole where it works best. You only need to drill the main leaf, and then stack the other leafs over the new hole location to make up the spring pack. I've done this many times with both front and rear spring packs. I've also cut off excess long single leafs to make them fit springs, and used my porta bandsaw to do it. Then just clean up the ends with a flapper disc.
Well, if you need that orientation to get proper axle location, you could always build a set of Cal-trac type bars to control any wind up.
Exactly, that's why the old s/s mopars bite so well, short front to control axle wrap and a long rear for ride. The old dodge super stock rear springs were quite the edge back in the day. ..
sounds like the perfect excuse to do an altered wheelbase, move the axle forward.... although not knowing more about your jalopy, that might be hard to do if the seat is already right in front of the tire
I need to keep the axle where it is, moving it foward would look more akward then it already does. I thought about re-drilling the main leaf, but the way the spring was made, there is a nice flat spot for the axle seat. I think you can see it in the picture. I'm just going to use it in reverse. I feel pretty sure it will be ok. Thanks again for all the input, Gene.
Is reversing the spring going to result in the axle/wheels positioned exactly where you want them? If it's just close then I'd always wish I'd done it differently. From what i see of the spring pack, I can't see any reason not to drill the centering hole exactly where you want in the main leaf, and then reassemble the pack.
^^^^^ Chief say “Only white man cut top off blanket then attach to bottom of same blanket to make longer”.
Looking at your picture of the spring, I think the only thing you will gain by drilling a second center bolt hole in the main leaf is a better chance of having the spring crack. The old hole will be in the flexy part of the spring. If you stack the springs backwards on top of each other with a couple of bolts through the bushings, that will help you visualize how reversing the lower leafs will look positioned on a new center bolt hole. I'm pretty sure you are going to find a gain of net zero, or very close to it.
I have drilled leafs quite a few times what a pain in the but. Never a main one, only other ones and never had any problems. I'm pretty convinced I'm going to use them, as I say backwards, and see what happens. Gene.
The Chrysler engineers made the springs offset for a very good reason. And even springmakers can't give you good advice [because they don't know the whole suspension design] If you are "hell bent" on turning the springs around 180° you need to make the springs very stiff [adding leaves] or add some forward control arms [to alleviate axle thrust] Now, the longer the spring [overall] the softer it is. And vice versa!! Chrysler offset the spring centre on Long Springs so the front half was stiffer to control "Axle Thrust" "Pinion Torque Reaction" and most importantly "Brake Torque" without sacrificing ride quality [by keeping the overall length longer] They also changed the angle of the spring so the Arc of suspension movement [red arrow] cancels out the spring lengthening [blue arrow] along the datum line. This prevents /minimalizes "roll-steer" Crawl under any factory built Leaf spring rear and you will observe the rear spring eye [shackles] is always higher than the front spring eye [hanger] This is roll-steer [RH turn with Body roll to the left] It doesn't stop there either you need to know the spring stiffness and the sprung weight , to calculate the spring load for static ride height and suspension frequency etc. If you turn the springs around , add a block of wood under the gas pedal [it is not good engineering practice ], regardless of what some "phone jockey" from Detroit Spring told you.
Done this for decades, and never had a spring break! The 2nd hole is rarely more than 1.5"-2" from the original, and it's not flexing hardly at all there. Plus the spring plate, and U bolts are still beyond the extra hole, so it's just not out where it's flexing or unsupported. Just isn't an issue at all since it's only one leaf. Not sure what the "pain" is in drilling a leaf spring? It takes me less than a minute per hole with cutting fluid and a Drill Hogg quality bit.
Never heard of Drill Hogg... will have to check them out. I have drilled a fair amount of leafs for Mopar springs. Mostly on a Mopar drag cars I built or helped build. Always had a problem with the bits grabbing, cutting oil or not. Gene.
Drill Hog bits are sold on Amazon, and other places. Lifetime warranty for breakage, and I've had my set for a long time and never sharpened one yet. They were $59 for a 21 piece set from 1/16"-1/2" and I think they're $139 now? Mine are the cobalt M42 bits, which are their highest grade I think?
I think its not; if it were the center bolt would be centered? All I've dealt with have been on center.
No, it's not a trailer spring. Most trailer springs are 1 3/4" wide, these are 2" wide. I had them made at a local spring shop when I was thinking of changing my '40 to parallel leafs on the front. I did a little more checking and it looks like I could move the center pin 3". That would give me enough room to put the springs in, short side foward. And I'm going to have to drill all of the leaves or they would stack wrong. Gene.
Trailer springs also have very small eyes on the ends that are only 3/4" so they don't accept bushings that are very large OD like car springs use.
Gene, my rear leaves are in long end to the front. There's only about 2" difference long to short. No problems or issues.
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